On Wednesday September 20 Corporal Donald Payne became the first Briton to admit to a war crime. Payne, 35, is accused of repeatedly banging the head of Baha Mousa, a 26-year-old Iraqi hotel worker, against a wall and floor until Mousa died - an accusation he denies. Payne called his Iraqi prisoners in the jail in Basra "the choir", because he liked to invite friends to hear them shriek with the pain he inflicted. "Corporal Payne enjoyed conducting what he called the choir," Julian Bevan QC told the court martial, which is taking place at Bulford Camp, in Wiltshire, and is expected to last for 16 weeks. "It was all done very openly."

The next day the home secretary, John Reid, went to Leyton, in east London, and told a room full of Muslims how to raise their kids so they won't grow up hateful. "Look for the telltale signs now and talk to them before their hatred grows and you risk losing them for ever," he told them.

The heckler in his midst simply provided Reid with proof of his moral righteousness. "This is Britain," Reid told the Labour party conference last week. "We will go where we please, we will discuss what we like, and we will never be browbeaten by bullies. That's what it means to be British."

Reid and Payne are two sides of the same coin. The bully of Basra exercises his right to demean and degrade wherever he pleases - the longstanding hallmarks of British colonialism. The hooligan from the Home Office vaunts the fair play, decency and social liberalism that ostensibly underpin core British values - a longstanding feature of Britain's self-delusion. Payne could have done with some parenting lessons of his own. Instead he was given a uniform and a gun. The arrogance we imbibe and the atrocities we export do not just coexist - they are codependent. That's also what it means to be British.

In Reid we find these qualities embodied in one man. Before he was the home secretary he was the defence secretary. He is set to have an impact on Britain's racial terrain analogous to the one he has had on the killing fields of Iraq: making a fragile situation worse.

Reid is not alone in this. Last month Ruth Kelly, the communities secretary, called for a "new and honest debate" about race in this country. This should not be mistaken for the "honest dialogue" Peter Hain wanted to launch in 2002 or the "rigorously honest" discussion David Blunkett sought to initiate in 2004. Quite what kind of deceitful debate they were engaged in back then and, given their huge parliamentary majority, what prevented their candour is not obvious. However, each followed a familiar pattern; promising blunt truths, but pandering to soft bigotry.

Kelly was no different. She insisted that it is "not racist" to voice concerns about immigration and asylum - a statement as true as it is fatuous since it depends on what those concerns are and what argument you're making. "We must not be censored by political correctness," she continued. "And we can't tiptoe around the issues." Are you thinking what I'm thinking? This was precisely the line taken by Michael Howard, the then Tory leader, before the last election. Far from being censored, the tabloids have been serving this tripe up as a staple for the past decade and New Labour has been swallowing it whole and then throwing it up whenever it gets nervous.

Any candid discussion of race, immigration and asylum that was not racist would not just acknowledge fear and prejudice but challenge them both. Since ministers are not able to do that about ethnic minorities, maybe they should start off with a subject with which they are more familiar. Let's have an open and honest discussion about white people.

Let's start by talking about how they don't want to integrate. The stubborn rump of around 10% of whites who, according to a 2002 Mori poll, are hostile to racial equality and antagonistic to the very existence of non-white people in this country. Given a percentage point either way, that is the consistent figure who believe that to be truly British you must be white and who do not believe it is important to respect the rights of minority groups.

Let's discuss their inability to choose moderate leaders and the propensity of the leaders they do choose to murder innocent civilians abroad by their thousands. Let's analyse their vulnerability to extremists such as the British National party, not to mention elsewhere in Europe, where fascism is once again a mainstream ideology.

Let's talk about the religious intolerance that rages in Scotland and Northern Ireland, and can be found in the highest levels of the state, where only Protestants can marry into royalty. And let's not forget the terrorists white people have been rearing at home for years, whether they are bombing Brick Lane, parliament or shopping centres in Manchester, and the no-go areas in housing estates, football terraces and boardrooms.

Only then perhaps will it become sufficiently apparent for those with insufficient imagination just how crude and crass the framing of the debate about Muslims has been. Any group of people will rightly bristle at the demand to answer collectively for the acts of individuals with whom they share an identity but over whom they have no control.

The tolerant, secular, liberal society into which Muslims are being asked to integrate lies somewhere between mythology and a work in progress and, the responsibility for transforming it into a lived reality lies with all of us. When it comes to poor whites lured by organised racism, Labour makes allowances.

'It is the poorest whites who feel the greatest anger because there is no way out for them," said Margaret Hodge about some of her constituents in Barking earlier this year. "The Labour party hasn't talked to these people. Part of the reason they switch to the BNP is they feel no one else is listening to them." When it comes to Muslims lured by fundamentalism, they make threats: but no one is listening to them either.

We should not be in denial that some young Muslims have become attracted to extremism and fundamentalism in recent years, but nor should we be in denial about why that should be. Muslims did not invent terrorism, nor did they introduce it to this country. Indeed, so long as Britain has occupied foreign lands, it has been vulnerable to sporadic acts of violence on its own soil.

Which brings us back to Payne, Reid and Kelly. For there is no honest conversation you can have about the strained racial fabric of this country at present without talking about the war. Once branded leftwing heresy, this truism is now intelligence-service orthodoxy on both sides of the Atlantic. It has been "a recruiting sergeant for extremists across the Muslim world", according to a leaked document allegedly written by a British MI6 officer attached to the Ministry of Defence; and a "cause celebre for jihadists", in the words of the US National Intelligence Estimate.

The war didn't invent fundamentalism; nor did it introduce it into Britain. But it has clearly exacerbated it. So long as the likes of Corporal Payne can conduct their torture choirs abroad, our racial landscape will be scarred; so long as the likes of Reid are preaching to the racist choir at home, it will never heal.

· Gary Younge will deliver the Claudia Jones memorial lecture - What's So Great about Integration? - on Tuesday October 12 at 7pm in the Guardian Newsroom, London. Tickets are limited; please email BMC@nuj.org.uk